Zhou Shaojie, Cui Shizhong, Wei Wutao, Chen Weihua, Mi Liwei
Center for Advanced Materials Research, Zhongyuan University of Technology Zhengzhou 450007 P. R. China
College of Chemistry and Molecular Engineering, Zhengzhou University Zhengzhou 450001 P. R. China
RSC Adv. 2018 Nov 5;8(65):37129-37135. doi: 10.1039/c8ra08019d. eCollection 2018 Nov 1.
The low utilization rate of active materials has been a critical obstacle for the industrialization of ultracapacitors. In this study, a thin layer of cross-structured ultrathin α-Ni(OH) nanosheets was successfully grown on the surface of a nickel foam as a high-conductivity framework by a vibratory water bath route under a low temperature (80 °C) and mild conditions. Combining the ultrathin α-Ni(OH) nanosheets and ultrashort electron transport, the strategy of a perfect intercalation structure of α-Ni(OH) and a thin layer of active material on a continuous conductive framework resulted in a high utilization rate of active material, which further achieved high specific capacitance of 213.55 F g at 1 A g in a two-electrode system and high capacitance retention from three to two electrode system (753.79 F g at 1 A g in the three-electrode system). Meanwhile, the device also achieved high energy density of 74.94 W h kg at power density of 197.4 W kg and still retained 24.87 W h kg at power density of 3642 W kg.
活性材料利用率低一直是超级电容器产业化的关键障碍。在本研究中，通过振动水浴法在低温（80°C）和温和条件下，在泡沫镍表面成功生长了一层交叉结构的超薄α-Ni(OH)纳米片作为高导电框架。结合超薄α-Ni(OH)纳米片和超短电子传输，α-Ni(OH)完美插层结构与连续导电框架上的活性材料薄层策略导致活性材料的高利用率，进而在两电极系统中实现了1 A g时213.55 F g的高比电容以及从三电极系统到两电极系统的高电容保持率（三电极系统中1 A g时为753.79 F g）。同时，该器件在功率密度为197.4 W kg时实现了74.94 W h kg的高能量密度，在功率密度为3642 W kg时仍保持24.87 W h kg。
